Mobile communication terminal device

ABSTRACT

A mobile communication terminal device whose authentication and settlement functions by noncontact proximity communication can be continuously used even after operating voltage from battery power drops is provided. Only when the supply of required power from a battery is lost, a security controller is controlled into a mode in which it operates with low power consumption and noncontact authentication and settlement functions are ensured by external electromagnetic field power. Specifically, the following is implemented: when there is the supply of required power from the battery, it is made possible to carry out high-performance, multifunctional authentication and settlement processing making good use of high-speed processing, mass storage, and the like which are the advantages of the security controller essentially driven by battery; and in an anomalous instance in which the battery remaining capacity is lost, it is made possible to carry out minimal authentication and settlement processing.

CROSS-REFERENCE TO RELATED APPLICATIONS

The disclosure of Japanese Patent Application No. 2009-181288 filed onAug. 4, 2009 including the specification, drawings and abstract isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a mobile communication terminal devicethat supports both noncontact proximity communication and wirelesscommunication longer in communication distance than noncontact proximitycommunication and includes a security controller utilized in securityprocessing in these types of communication and to a technologyeffectively applicable to, for example, a cellular phone havingauthentication and settlement functions.

A mobile terminal device having a noncontact proximity communicationfunction refers to a device originally intended to be mainly used forany other purpose (cellular phone mainly intended for a telephone callfunction or the like) with noncontact authentication and settlementfunctions added thereto. Single-function card terminal devices dedicatedto noncontact authentication and settlement functions basically do notuse a battery. They receive a carrier wave (carrier) generated by anoppositely placed reader/writer and operates using its electromagneticfield power. When a mobile terminal device is additionally provided withits noncontact authentication and settlement functions, it consumes morepower than card terminal devices. As a result, it cannot carry out itsfunctions by supply of power by electromagnetic field transfer and musteventually use a battery. The reason for this is as follows: unlike cardterminal devices, mobile terminal devices are made multifunctional sothat a security controller carrying out security processing fornoncontact authentication and settlement can be used also in mobilecommunication processing; and for this purpose, the performance of theCPU of the security controller and further the capacity of a storagedevice are increased and this increases power consumption.

The mobile terminal device functions on power supplied from a battery.Because of use for the principal purpose of the device, however, thepower from the battery is consumed and it may get itself cornered in asituation in which it cannot carry out its functions for the principalpurpose. In the mobile terminal device, power supply capability isestimated by monitoring the value of the output voltage of the battery.When the estimated value becomes equal to or lower than a certainvoltage value, it is determined that the device has been brought into anunusable state and the functions for the principal purpose are stopped.However, the noncontact authentication and settlement functions do notconsume so much power as the principal purpose. Therefore, even in sucha state of power supply capability that the functions for the principalpurpose cannot be carried out, there are the following cases: caseswhere the noncontact authentication and settlement functions can becarried out until the value is reduced to the next predetermined voltagevalue.

However, the noncontact authentication and settlement functions equippedin a mobile terminal device consume more power than those ofsingle-function card terminal devices dedicated to noncontactauthentication and settlement functions. Even though it seems to beoperable according to the state of its battery self-discharging, theperiod for which it is operable is very short. There is not a highpossibility that its noncontact authentication and settlement functionscan be used during a period for which these functions can be carried outafter the stop of the functions for the principal purpose. As a result,there is a high possibility that noncontact authentication or settlementcannot be carried out, either unless the supplying capability of thebattery is restored. A mobile terminal device containing electronicinformation for the user's commuter pass will be taken as an example. Ifits noncontact authentication functions cannot be used because ofbattery remaining capacity shortage, the terminal device cannot operateas a commuter pass. In this case, the user must pay a fare in cashthough he/she carries the pass unless the battery is recharged to bringthe terminal device into a usable state.

Patent Document 1 describes a technology for reducing the powerconsumption of a cellular phone provided with, in addition to atelephone function, a noncontact IC card function part for carrying outa noncontact authentication function and a settlement function.According to this, to lengthen the life of a battery, battery power issupplied to the noncontact IC card function part when electromagneticfield power becomes short.

-   [Patent Document 1] Japanese Unexamined Patent Publication No.    2006-60700

SUMMARY OF THE INVENTION

However, even though in an attempt to lengthen the life of a battery,battery power is supplied to a noncontact IC card function part whenelectromagnetic field power is short, the following takes place. In thefirst place, the power consumption of the noncontact IC card functionpart is higher than that of card terminal devices dedicated tononcontact authentication and settlement functions. In this situation,it is expected that only with electromagnetic field power, powershortage occurs in almost all cases and the life of a battery cannot belengthened as intended in many cases.

It is an object of the invention is to provide a mobile communicationterminal device whose authentication and settlement functions bynoncontact proximity communication (proximity noncontact communication)can be uninterruptedly used even when operating voltage from batterypower drops.

The above and other objects and novel features of the invention will beapparent from the description in this specification and the accompanyingdrawings.

The following is a brief description of the gist of the representativeelements of the invention laid open in this application:

Only when required power supply from a battery is lost, a securitycontroller is controlled into a mode in which it operates with low powerconsumption and noncontact authentication and settlement functions areensured by external electromagnetic field power. Thus, even when thebattery remaining capacity is lost by use of the communication functionfor the principal purpose, noncontact authentication and settlementfunctions can be used. More specific description will be given. Whenthere is supply of required power from a battery, high-performance,multifunctional authentication and settlement processing can be carriedout by making good use of high-speed processing, mass storage, and thelike which are advantages of security controllers fundamentally drivenby a battery. In an anomalous instance in which the battery remainingcapacity is lost, it is made possible to carry out minimalauthentication and settlement processing.

The following is a brief description of the gist of effects obtained bythe representative elements of the invention laid open in thisapplication:

A mobile communication terminal device supports both noncontactproximity communication and wireless communication longer incommunication distance than noncontact proximity communication andincludes a security controller that can be utilized in securityprocessing in these types of communication. In this terminal device,authentication and settlement functions by noncontact proximitycommunication can be uninterruptedly stably used even when operatingvoltage from battery power drops.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of a mobilecommunication terminal device of the invention;

FIG. 2 is a block diagram illustrating a concrete example of anoncontact proximity communication unit 2;

FIG. 3 is a block diagram illustrating an example of a securitycontroller;

FIG. 4 is a block diagram illustrating an example of a voltagemonitoring circuit;

FIG. 5 is a block diagram illustrating an example of a mode of supplyingoperating voltage to an internal circuit by a power supply control unit;

FIG. 6 is a block diagram illustrating an example of the clock supplysystem of a security controller;

FIG. 7 is a block diagram illustrating an example of a clock controlunit;

FIG. 8 is a block diagram illustrating another example of a clockcontrol unit;

FIG. 9 is a block diagram illustrating another example of the clocksupply system of a security controller;

FIG. 10 is a block diagram illustrating an example of a control logic ofa clock control circuit that implements the functions of the clocksupply system in FIG. 9;

FIG. 11 is a block diagram illustrating an example of a configurationfor making it possible to select a program start address using a powersupply control circuit;

FIG. 12 is a memory map diagram illustrating an example in which a firstprogram PGM_F and a second program PGM_S are mapped to fixed memoryareas;

FIG. 13 is a memory map diagram illustrating an example in which a firstprogram PGM_F and a second program PGM_S can be mapped to arbitrarymemory areas;

FIG. 14 is a flowchart illustrating an example of operation that takesplace when the power to a security controller is turned on;

FIG. 15 is a block diagram illustrating an example in which programchange control, executed through program area activation control, iscarried out;

FIG. 16 is a block diagram illustrating an example of a mobilecommunication terminal device in which a security controller determinesbattery voltage VDDb;

FIG. 17 is a block diagram illustrating an example of the configurationof the security controller in FIG. 16;

FIG. 18 is a flowchart illustrating an example of operation that takesplace when the power to the security controller in FIG. 16 is turned on;

FIG. 19 is a block diagram of a mobile communication terminal device soconfigured that battery voltage VDDb is passed to a security controller4 through a mobile communication unit unlike the configuration in FIG.16;

FIG. 20 is a block diagram of a mobile communication terminal deviceused in cases where a noncontact proximity communication unit determinesbattery voltage VDDb;

FIG. 21 is a block diagram of the security controller in FIG. 20;

FIG. 22 is a flowchart illustrating an example of operation that takesplace when the power to the security controller in FIG. 20 is turned on;

FIG. 23 is a block diagram of a mobile communication terminal deviceused when both a noncontact proximity communication unit and a mobilecommunication unit determine battery voltage VDDb;

FIG. 24 is a block diagram of the security controller in FIG. 23; and

FIG. 25 is a flowchart illustrating low power consumption control of thesecurity controller in FIG. 24.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

1. Overview of Embodiments

First, description will be given to the overview of embodimentsrepresentative of the invention disclosed in this specification. Theparenthesized reference numerals in the drawings referred to in thedescription of the overview of the representative embodiments justindicate examples of what is contained in the concepts of constituentelements to which the numerals are affixed.

<1> A mobile communication terminal device (1) in a representativeembodiment of the invention includes: a noncontact proximitycommunication unit (2) that carries out noncontact proximitycommunication; a wireless communication unit (3) that carries outwireless communication longer in communication distance than thenoncontact proximity communication and carries out input/output controlfor this wireless communication; a security controller (4) utilized insecurity processing for the noncontact proximity communication unit andthe wireless communication unit; and a battery (5). The noncontactproximity communication unit receives electromagnetic field power from acarrier in noncontact proximity communication and battery power from thebattery and operates and supplies the received power to the securitycontroller. The security controller determines whether or not voltage ofpower (VDDA) supplied from the noncontact proximity communication unithas reached a specified level (Vref). When it is determined that thevoltage has not reached the specified level, control is carried out toreduce the electricity consumption of the security controller.

As a result, only when supply of required power from the battery islost, the security controller is operated with low power consumption andnoncontact authentication and settlement functions are ensured byexternal electromagnetic field power. Therefore, even when the batteryremaining capacity is reduced by operation of the wireless communicationunit, it is possible to uninterruptedly and stably use noncontactauthentication and settlement functions using the security controllerthrough the noncontact proximity communication unit.

<2> In the mobile communication terminal device in Section <1> above,the security controller includes a clock control circuit (25) thatgenerates a synchronous clock signal for internal operation. When it isdetermined that the specified level has not been reached, the clockcontrol circuit reduces the frequency of the synchronous clock signal(CK in FIGS. 7 and 8) as compared with when the specified level has beenreached. By reducing the clock signal frequency, it is made possible toreduce the electricity consumption of the entire security controller andmake good use of only minimal authentication and settlement processingby noncontact proximity communication (proximity noncontactcommunication).

<3> In the mobile communication terminal device in Section <1> above,the security controller includes a clock control circuit (25) thatgenerates a synchronous clock signal for internal operation. When it isdetermined that the specified level has not been reached, the clockcontrol circuit interrupts the supply of a synchronous clock signal (CK1in FIG. 9) to a circuit utilized only in security processing for thewireless communication unit. Thus the supply of a synchronous clocksignal to a circuit utilized only in security processing for thewireless communication unit that has already been inoperable because ofreduced battery remaining capacity is interrupted. As a result, it ispossible to make good use of only minimal authentication and settlementprocessing by proximity noncontact communication.

<4> In the mobile communication terminal device in any of Sections <1>to <3> above, the security controller carries out the followingprocessing when it is determined that the specified level has not beenreached: it interrupts operating power supply (Vdd2 in FIG. 5) to acircuit utilized only in security processing for the wirelesscommunication unit. Thus operating power supply to a circuit utilizedonly in security processing for the wireless communication unit that hasalready been inoperable because of reduced battery remaining capacity isinterrupted. As a result, it is possible to make good use of onlyminimal authentication and settlement processing by proximity noncontactcommunication.

<5> In the mobile communication terminal device in Section <4> above,the security controller includes: a program memory unit (20); aprocessor (21) that executes a program held by the program memory unit;a first circuit (22) used in security processing for the wirelesscommunication unit; and a second circuit (23) used in securityprocessing for the noncontact proximity communication unit. The programmemory unit holds: a first initialization program (MIPGM) forinitializing a circuit used in security processing for the wirelesscommunication unit; a second initialization program (NIPGM) forinitializing a circuit used in security processing for the noncontactproximity communication unit; a first security processing program(MSPGM, RTOS) used in security processing for the wireless communicationunit; and a second security processing program (NSPGM) used in securityprocessing for the noncontact proximity communication unit.

<6> In the mobile communication terminal device in Section <5> above,the program memory unit includes: a first program memory unit (41) forstoring the first initialization program and the first securityprocessing program; and a second program memory unit (40) for storingthe second initialization program and the second security processingprogram. There are two selectable operation modes. In first operationmode, operating power supply is supplied both to the first programmemory unit and to the second program memory unit. In second operationmode, operating power supply is supplied only to the second programmemory unit. When operating power supply to a circuit utilized only insecurity processing for the wireless communication unit is interrupted,the second operation mode is selected. As the result of the programmemory unit being divided as mentioned above, the electricityconsumption can be further reduced when the security controller isoperated by electromagnetic field power only.

<7> In the mobile communication terminal device in Section <6> above,the processor carries out the following processing on a case-by-casebasis: when it is determined that the voltage has reached the specifiedlevel at power-on reset, it executes the first initialization programand the second initialization program to carry out initializationprocessing; and when it is determined that the voltage has not reachedthe specified level, it executes the second initialization program tocarry out initialization processing. When the security controller isoperated by electromagnetic field power only, wasteful electricityconsumption by initialization of an unnecessary circuit that is not usedcan be reduced.

<8> In the mobile communication terminal device in any of Sections <1>to <7> above, the noncontact proximity communication unit carries outthe following processing on a case-by-case basis: in cases where voltagefrom the battery power is higher than a predetermined voltage, itsupplies the electromagnetic field power to the security controller whenit is produced, and supplies battery power thereto when it is notproduced; and in cases where voltage from the battery power is equal toor lower than the predetermined voltage, it supplies the electromagneticfield power to the security controller and interrupts supply of thebattery power (13 in FIG. 2).

When the noncontact proximity communication unit carries outcommunication operation, electromagnetic field power is constantlysupplied to the security controller. When the security controllerdetermines that voltage from electromagnetic field power is voltagelower than the specified voltage and noncontact proximity communicationis carried out, the security controller can be operated with reducedpower consumption regardless of voltage from battery power supply. Whenthe noncontact proximity communication unit carries out communicationoperation, it is based on the presupposition that the wirelesscommunication unit will not carry out communication.

<9> In the mobile communication terminal device in any of Sections <1>to <7> above, the noncontact proximity communication unit carries outthe following processing on a case-by-case basis: when voltage from thebattery power is higher than the predetermined voltage, it supplies atleast battery power to the security controller; and when voltage fromthe battery power is equal to or lower than the predetermined voltage,it supplies the electromagnetic field power to the security controllerand interrupts supply of the battery power.

<10> In the mobile communication terminal device in Section <8> or <9>above, the specified voltage and the predetermined voltage are equal toeach other.

<11> A mobile communication terminal device in another embodiment of theinvention includes: a noncontact proximity communication unit thatcarries out noncontact proximity communication; a wireless communicationunit that carries out wireless communication longer in communicationdistance than the noncontact proximity communication and carries outinput/output control for this wireless communication; a securitycontroller utilized in security processing for the noncontact proximitycommunication unit and the wireless communication unit; and a battery.The noncontact proximity communication unit receives electromagneticfield power from a carrier in noncontact proximity communication andbattery power from the battery and determines whether or not voltagefrom the received battery power has reached a specified level (30B inFIG. 20). The security controller receives the result of thedetermination and when it is determined that the voltage has not reachedthe specified level, it carries out control so as to reduce theelectricity consumption of the security controller. This makesunnecessary to provide the determination function aside from thesecurity controller. When the noncontact proximity communication unitselectively supplies electromagnetic field power or battery power to thesecurity controller in the mobile communication terminal device inSection <1> above, it is required to take the following measure: thedetermination function is provided not only in the security controllerbut also in the noncontact proximity communication unit.

<12> A mobile communication terminal device in further anotherembodiment of the invention includes: a noncontact proximitycommunication unit that carries out noncontact proximity communication;a wireless communication unit that carries out wireless communicationlonger in communication distance than the noncontact proximitycommunication and carries out input/output control for this wirelesscommunication; a security controller utilized in security processing forthe noncontact proximity communication unit and the wirelesscommunication unit; and a battery. The noncontact proximitycommunication unit receives electromagnetic field power from a carrierin noncontact proximity communication and battery power from the batteryand determines whether or not voltage from the received battery powerhas reached a specified level. When it is determined that the specifiedlevel has not been reached, it issues a command (NCMD) instructing thesecurity controller to carry out control so as to reduce electricityconsumption (30B in FIG. 23). The wireless communication unit receivesbattery power from the battery and determines whether or not voltagefrom the received battery power has reached a specified level. When thespecified level has not been reached, it issues a command (MCMD)instructing the security controller to carry out control so as to reduceelectricity consumption (30C in FIG. 23)

2. Details of Embodiments

More detailed description will be given to the embodiments.

FIG. 1 illustrates an example of a mobile communication terminal deviceof the invention. The mobile communication terminal device (PDA) 1 shownin the drawing is formed by adding an IC card function including anoncontact proximity communication function to a cellular phone thatcarries out so-called mobile communication. Specifically, the mobilecommunication terminal device 1 includes: a noncontact proximitycommunication unit (NFDCOM) 2 that carries out noncontact proximitycommunication; a mobile communication unit (MBLCOM) 3 as a wirelesscommunication unit that carries out wireless communication (for example,mobile communication with a cellular phone or the like) longer incommunication distance than the noncontact proximity communication andcarries out input/output control for this wireless communication; asecurity controller (SCRCNT) 4 utilized in security processing for thenoncontact proximity communication unit 2 and the mobile communicationunit 3; and a battery (BTRY) 5.

Though not especially shown in the drawing, the mobile communicationunit 3 includes: a high-frequency unit coupled to an antenna 10; a baseband unit that carries out protocol processing, such as modulation oftransmit data and demodulation of received signals; an applicationprocessor unit that carries out data processing, such as generation oftransmit data and display control on received data; a liquid crystaldisplay, a keyboard, and the like. Provided with these members, themobile communication unit 3 carries out the functions of a cellularphone and is operated using battery voltage VDDb from the battery 5 asoperating power supply.

The noncontact proximity communication unit 2 transmits and receivesdata to and from an oppositely placed reader/writer (RDWR) 6 inclose-range wireless communication. Further, it receives electromagneticfield power from a carrier from the reader/writer 6 and battery powerfrom the battery and supplies the received power to the securitycontroller 4.

Preliminary description will be given to a concrete example of thenoncontact proximity communication unit 2 with reference to FIG. 2. Anantenna 11 and a capacitor 19 coupled in parallel therewith form aresonance circuit. A power supply circuit 12 is comprised of arectifying circuit and a smoothing capacitor, neither of which is shownin the drawing. It rectifies and smoothes a carrier (alternating-currentsignal) as an electromagnetic wave power in noncontact communicationreceived at the antenna 11 to generate received voltage VDDr. Anoperating voltage determination and selection circuit 13 is inputtedwith the received voltage VDDr and battery voltage VDDb from the battery5: When the battery voltage VDDb is higher than a predetermined voltage,for example, a voltage expected as received voltage VDDr (expectedreceived voltage), the operating voltage determination and selectioncircuit 13 carries out the following processing on a case-by-case basis:in cases where the electromagnetic field power has been produced, itoutputs received voltage VDDr from this electromagnetic field power asoperating voltage VDDA; and in cases where the electromagnetic fieldpower has not been produced, it outputs the battery voltage VDDb asoperating voltage VDDA. When the battery voltage VDDb is equal to orlower than the predetermined voltage, the operating voltagedetermination and selection circuit 13 outputs the received voltage VDDras operating voltage VDDA. The operating voltage VDDA is used asoperating power supply to an internal circuit 14 and the securitycontroller 4. When the inputted operating voltage VDDA is higher thanthe upper limit of operation enable voltage, the internal circuit 14steps down the operating voltage VDDA to generate expected receivedvoltage expected as the received voltage VDDr and uses it as internaloperating voltage.

The internal circuit 14 is comprised of a reception unit 15, atransmission unit 16, a control unit 17, and a memory 18. The receptionunit 14 demodulates data superimposed on an alternating-current signalreceived by the antenna 11 and supplies it as digital received data tothe control unit 17. The transmission unit 16 modulates analternating-current signal as a carrier received by the antenna 11 basedon digital transmit data supplied from the control unit 17. The memorytemporarily holds transmit and received data.

As illustrated in FIG. 3 as an example, the security controller 4includes: a program memory unit (PMRY) 20; a processor (PRSC) 21 thatcarries out a program held by the program memory unit 20; an mobilecommunication unit interface circuit (MFNC) 22 used for interface withthe mobile communication unit 3; a noncontact proximity communicationunit interface circuit (NFNC) 23 used for interface with the noncontactproximity communication unit 2; a power supply control unit (PWCNT) 24that controls power supply to the security controller 4; and a clockcontrol unit (CKCNT) 25 that controls the clock of the securitycontroller 4. These members are coupled to an internal bus 26. Themobile communication unit interface circuit 22 is coupled to the mobilecommunication unit 3 and the noncontact proximity communication unitinterface circuit 23 is coupled to the noncontact proximitycommunication unit 2.

The power supply control unit 24 includes a voltage monitoring circuit(VdMNT) 30. As illustrated in FIG. 4 as an example, the voltagemonitoring circuit 30 determines whether or not the operating voltageVDDA supplied from the noncontact proximity communication unit 2 ishigher than a specified level Vref through a comparator (CMP) 31 andoutputs a determination signal φdt. The specified level Vref isgenerated at a reference voltage generation circuit (VrGNR) 32. Thoughnot especially limited, the specified level Vref is defined as a voltageat the lowest level required for the security controller 4 to use allits functions to operate, that is, all functionality operationguaranteed voltage. This all functionality operation guaranteed voltageis, for example, a voltage identical with or slightly higher than thepredetermined voltage determined by the operating voltage determinationand selection circuit 13 of the noncontact proximity communication unit2.

The security controller 4 carries out low-power consumption controlbased on the determination signal 4 dt generated at the voltagemonitoring circuit 30. Hereafter, detailed description will be given tothis control mode with low power consumption with multiple examplescited.

<<Control of Supply/Interruption of Operating Voltage>>

A first control mode with low power consumption is a method in which thesupply/interruption of operating voltage is controlled.

As illustrated in FIG. 5 as an example, the power supply control unit 30includes: a second power supply unit 34 that supplies operating voltageVdd2 to a circuit portion utilized only in security processing for themobile communication unit 3 in the security controller 4; and a firstpower supply unit 35 that supplies operating power supply Vdd1 to theother circuit portions. The second power supply unit 34 interrupts thesupply of second operating voltage Vdd2 when the determination signalφdt indicates that the specified level Vref has not been exceeded; andthe first power supply unit 35 constantly supplies first operatingvoltage Vdd1.

In FIG. 5, the program memory unit 20 is divided into a first programmemory unit (20_F) 40 and a second program memory unit (20_S) 41, whichindividually receive operating power supply so that memory operation isenabled. Though not especially limited, the second program memory unit41 stores a security processing program (MSPGM) for mobilecommunication, a security processing initialization program (MIPGM) formobile communication, and a real-time OS (RTOS). Though not especiallylimited, the first program memory unit 40 stores a security processingprogram (NSPGM) for noncontact proximity communication and a securityprocessing initialization program (NIPGM) for noncontact proximitycommunication.

According to the example in FIG. 5, the operating voltage Vdd2 outputtedby the second power supply unit 34 is supplied to the second programmemory unit 41 and the mobile communication unit interface circuit(MFNC) 22. The operating voltage Vdd1 outputted by the first powersupply unit 35 is supplied to the first program memory unit 40,processor 21, clock control unit 25, and noncontact proximitycommunication unit interface circuit (MFNC) 23.

As the result of the foregoing, the following processing is carried outwhen it is determined that the operating voltage VDDA is not higher thanthe specified level Vref: the supply of operating voltage Vdd2 to thecircuits 22, 41 utilized only in security processing for the mobilecommunication is interrupted. Thus the supply of operating voltage Vdd2to the circuits utilized only in security processing for mobilecommunication that have already been inoperable because of reducedbattery remaining capacity is interrupted. As a result, it is possibleto make good use of only minimal authentication and settlementprocessing by proximity noncontact communication. Especially, theoperating voltage determination and selection circuit 13 of thenoncontact proximity communication unit 2 carries out the followingprocessing when the received voltage VDDr is generated at the powersupply circuit 12. That is, it carries out the following processing whennoncontact proximity communication is carried out: even though thebattery voltage VDDb is not equal to or lower than the specified level,it supplies the security controller 4 with the received voltage VDDr asoperating voltage VDDA. Therefore, when noncontact proximitycommunication is carried out, the security controller 4 can be operatedwith reduced power consumption regardless of the voltage of batterypower supply. This is based on the presupposition that when thenoncontact proximity communication unit carries out communicationoperation, the wireless communication unit does not carry outcommunication. In short, when the noncontact proximity communicationunit 2 carries out noncontact proximity communication, the mobilecommunication unit 3 does not carry out mobile communication and thesecurity controller 4 only has to be capable of security processing fornoncontact proximity communication. The security controller is suppliedwith the received voltage VDDr as operating voltage VDDA and operatingpower supply to the mobile communication unit interface circuit 22 andthe second program memory unit 41 that are unnecessary for noncontactauthentication and settlement is interrupted.

<<Clock Frequency Control>>

A second control mode with low power consumption is a method in which aclock frequency is controlled.

FIG. 6 illustrates an example of the clock supply system of the securitycontroller 4. The clock control unit (clock control circuit) 25 receivesthe determination signal φdt and controls the frequency of a clocksignal CK according to its value. Specifically, when it is determinedthat the operating voltage VDD2 it not higher than the specified levelVref, the following processing is carried out: the frequency of theclock signal CK is made lower than when it is determined that theoperating voltage VDD2 it higher than the specified level Vref. Byreducing the clock signal frequency, it is made possible to reduce theelectricity consumption of the entire security controller and make gooduse of only minimal authentication and settlement processing byproximity noncontact communication.

FIG. 7 illustrates an example of the clock control unit 25. In thisexample, the clock control unit 25 includes a first clock source(CKSRC_F) 46 that generates a clock signal CK1 and a second clock source(CKSRC_S) 42 that generates a clock signal CK2. It causes either clocksource to perform oscillating operation according to the value of thedetermination signal φdt to generate a clock signal CK. The clock signalCK1 is higher in frequency than the clock signal CK2. When thedetermination signal φdt indicates that the operating voltage VDD2 isequal to or lower than the specified voltage Vref, the second clocksource 42 is caused to perform oscillating operation to generate a clocksignal CK. In the other cases, the first clock source 41 is caused toperform oscillating operation to generate a clock signal CK. The outputof a clock source that is not performing oscillating operation is keptin high output impedance state. When the operation of the second clocksource 42 is selected, the electricity consumption by the oscillatingoperation of the clock source is reduced.

FIG. 8 illustrates another example of the clock control unit 25. In thisexample, the clock control unit 25 includes: a first clock source(CKSRC) 43 that generates a clock signal CK1; a frequency dividercircuit (CKDIV) 44 that divides the frequency of the clock signal CK1 togenerate a clock signal CK2; and a clock selector circuit (CKSLC) 45.Either clock signal CK1 or CK2 is selected according to the value of thedetermination signal φdt. When the determination signal φdt indicatesthat the operating voltage VDD2 is equal to or lower than the specifiedvoltage Vref, the clock signal CK2 is selected and in the other cases,the clock signal CK1 is selected. Since clock sources can be unified,the chip occupation area of the clock control circuit 25 can be reduced,for example, when the security controller 4 is formed in one chip as asemiconductor integrated circuit or on other like occasions. The clocksource need not be formed in the security controller 4 and the foregoingis the same with cases where a clock signal is supplied from an externaloscillator or an external source.

The adoption of the above clock frequency control makes it possible forthe security controller 4 to determine the remaining power of thebattery 5 by monitoring the value of the supplied operating voltageVDD2. Power saving operation using the received voltage VDDr fromelectromagnetic field power can be carried out in either of thefollowing cases: cases where mobile communication is not carried out andnoncontact proximity communication is carried out even though there ispower remaining in the battery; and cases where battery power supply isinterrupted.

<<Control of Supply/Interruption of Clock Signal>>

A third control mode with low power consumption is a method in whichsupply/interruption of a clock signal is controlled.

FIG. 9 illustrates another example of the clock supply system of thesecurity controller 4. The clock control circuit 25 supplies a clocksignal CKm to the mobile communication unit interface circuit 22 usedonly in security processing for mobile communication and a clock signalCKn to the other circuit portions. Though not especially limited, theclock signals CKm and CKn are identical in frequency. In the example inFIG. 9, the clock control unit 25 operates on a case-by-case basis asfollows: when the determination signal φdt indicates that the operatingvoltage VDDA is higher than the specified voltage Vref, it supplies boththe clock signals CKm and CKn to the respective circuits; and when thedetermination signal φdt indicates that the operating voltage VDDA islower than the specified voltage Vref, it interrupts the supply of clocksignal CKm. The following can be implemented by selectively interruptingthe supply of clock signal CKm: it is made possible to reduce theelectricity consumption of the entire security controller and make gooduse of only minimal authentication and settlement processing byproximity noncontact communication.

FIG. 10 illustrates an example of the control logic of the clock controlcircuit 25 for carrying out the function in FIG. 9. The clock controlcircuit 25 includes a clock source (CKSRC) 50 that outputs a clocksignal CKn. In response to a high level of the determination signal φdt,it outputs the clock signal CKn as clock signal CKm from a NAND gate 51.

<<Program Change>>

A fourth control mode with low power consumption is a method in whichchanging of programs executed by the processor 21 is controlled.

FIG. 11 illustrates an example of a configuration for making it possibleto select a program start address using a power supply control circuit.A first start address register (SAREG_F) 61 holds the start address of afirst program for making all the functions of the security controller 4available under the control of the processor 21. A second start addressregister (SAREG_S) 62 holds the start address of a second program forcarrying out security processing for noncontact proximity communicationof the security controller 4 under the control of the processor 21.Though not especially limited, the program start address is swiftly readat power-on reset of the security controller 4 or at system reset and itis desirable that this address information should be held before andafter a reset. Therefore, the first start address register 61 and thesecond start address register 62 may be a dedicated nonvolatile memoryor part of a nonvolatile memory for making address informationchangeable. They may be fixedly held by ROM or the like. An addressselector 60 initially sets the following on the program counter (PC),not shown, of the processor 21 on a case-by-case basis at power-on resetof the security controller 4 or at system reset as follows: when thedetermination signal φdt indicates that the operating voltage VDDA islower than the specified voltage Vref, it sets the start address of thesecond start address register 62; and when the determination signal 4 dtindicates that the operating voltage VDDA is higher than the specifiedvoltage Vref, it sets the start address of the first start addressregister 61. Though not especially limited, the first program iscomprised of the following programs stored from the start address of itsprogram storage area in the following order: the security processinginitialization program (MIPGM) for mobile communication; the securityprocessing initialization program (NIPGM) for noncontact proximitycommunication, the real-time OS (RTOS); the security processing program(MSPGM) for mobile communication; and the security processing program(NSPGM) for noncontact proximity communication. The second program iscomprised of the following programs stored from the start address of itsprogram storage area in the following order: the security processinginitialization program (NIPGM) for noncontact proximity communication;and the security processing program (NSPGM) for noncontact proximitycommunication. As illustrated in FIG. 12 as an example, the firstprogram PGM_F and the second program PGM_S are stored in the programmemory 20 completely separately from each other. The first program PGM_Fis stored in the area whose initial address is address 0 and the secondprogram PGM_S is stored in the area whose initial address is address Y.When it is enabled to rewrite the first start address register (SAREG_F)61 and the second start address register (SAREG_S) 62 by mapping theminto a memory space as illustrated in FIG. 13, the first program PGM_Fand the second program PGM_S can be mapped into an arbitrary memoryarea.

With the above configuration, the processing is carried out asillustrated in FIG. 14 as an example. That is, when the power to thesecurity controller 4 is turned on, it is determined whether or not itsoperating voltage VDDA is higher than the specified voltage Vref (S1).When it is higher than, for example, the specified voltage Vref (=2.2V),the address of the first start address register (SAREG_F) 61 is loadedto the program counter (PC) of the processor 21 (S2). Then the executionof the first program is started at the loaded address and all thefunctions of the security controller 4 are made available (S3). When theoperating voltage is equal to or lower than, for example, the specifiedvoltage Vref (=2.2V), the address of the second start address register(SAREG_S) 62 is loaded to the program counter (PC) of the processor 21(S4). Then the execution of the second program is started at the loadedaddress and in the security controller 4, only security processing fornoncontact proximity communication available is made (S5). When thebattery power drops, in the security controller 4, only initializationoperation required for security processing for noncontact proximitycommunication is performed and initialization operation required forsecurity processing for mobile communication is not performed.Therefore, it is possible to omit wasteful processing in processingusing a little power from electromagnetic field power and guaranteeswift transition to noncontact proximity communication. In the examplein FIG. 14, voltage level is determined only when power supply is turnedon. Instead, it may be monitored as required or may be constantlymonitored and the state of the security controller may be modifiedaccording thereto.

FIG. 15 illustrates an example in which changing of executed programs iscontrolled by program area activation control. A storage unit (storagearea) 71 for the first program (PGM_F) holds the following programs fromthe start address of its storage area in the following order: thesecurity processing initialization program (MIPGM) for mobilecommunication; the security processing initialization program (NIPGM)for noncontact proximity communication; the real-time OS (RTOS); thesecurity processing program (MSPGM) for mobile communication; and thesecurity processing program (NSPGM) for noncontact proximitycommunication. A storage unit (storage area) 72 for the second program(PGM_S) holds the following programs from the start address of itsstorage unit (storage area) in the following order: the securityprocessing initialization program (NIPGM) for noncontact proximitycommunication; and the security processing program (NSPGM) fornoncontact proximity communication. The program storage units (programstorage area) 71, 72 may be separate memories or may be different memoryblocks in an identical memory; however, they are at least selectivelyactivated. A program selector (PGMSLC) 70 makes the following storageunits (storage areas) active by an activation control signal φmen on acase-by-case basis at power-on reset of the security controller 4 or atsystem reset as follows: when the determination signal φdt indicatesthat the operating voltage VDDA is lower than the specified voltageVref, it makes the second program storage unit (second program storagearea) 72 active; and when the determination signal φdt indicates thatthe operating voltage VDDA is higher than the specified voltage Vref, itmakes the first program storage unit (first program storage area) 71active. One activated storage unit (storage area) is mapped to thememory space of the processor 21 and instructions are sequentiallyexecuted from that at the initial address of this storage unit (storagearea). Also with the configuration in FIG. 15, in the securitycontroller 4, only initialization operation required for securityprocessing for noncontact proximity communication is carried out whenthe battery power drops. Initialization operation required for securityprocessing for mobile communication is not carried out. Therefore, it ispossible to omit wasteful processing in processing using a little powerfrom electromagnetic field power and guarantee swift transition tononcontact proximity communication.

<<Determination of Battery Voltage by Security Controller>>

In the above-described controls with low power consumption, the securitycontroller 4 determines the level of operating voltage VDDA. Descriptionwill be given to a fifth control mode with low power consumption inwhich the battery voltage VDDb is determined by the security controller4.

As illustrated in FIG. 16 as an example, battery voltage VDDb isdirectly supplied from the battery 5 to the security controller 4. Atthis time, as illustrated in FIG. 17 as an example, the securitycontroller 4 determines whether or not the battery voltage VDDb hasreached the specified voltage Vref by the voltage monitoring circuit30A. The resulting determination signal φdt is used in, for example, theselection of a program start address described with reference to FIG.11. In this case, the processing is carried out as illustrated in FIG.18. That is, when the power to the security controller 4 is turned on,it is determined whether or not the battery voltage VDDb is higher thanthe specified voltage Vref (S6). When it is higher than, for example,the specified voltage Vref (=2.2V), the address of the first startaddress register (SAREG_F) 61 is loaded to the program counter (PC) ofthe processor 21 (S2). Then the execution of the first program isstarted at the loaded address and all the functions of the securitycontroller 4 are made available (S3). Meanwhile, when the batteryvoltage is equal to or lower than, for example, the specified voltageVref (=2.2V), the address of the second start address register (SAREG_S)62 is loaded to the program counter (PC) of the processor 21 (S4). Thenthe execution of the second program started at the loaded address and inthe security controller 4, only security processing for noncontactproximity communication is made available (S5). The mode for low powerconsumption control using the determination signal φdt may be any of thefirst mode to the third mode. In the example in FIG. 18, voltage levelis determined only when power supply is turned on. Instead, it may bemonitored as required or may be constantly monitored and the state ofthe security controller may be modified according thereto.

Unlike the configuration in FIG. 16, the battery voltage VDDb may bepassed from the mobile communication unit 3 to the security controller 4as illustrated in FIG. 19.

<<Determination of Battery Voltage by Noncontact Proximity CommunicationUnit>>

In the above-described controls with low power consumption, the securitycontroller 4 determines the operating voltage VDDA or the batteryvoltage. Description will be given to a sixth control mode with lowpower consumption in which the battery voltage VDDb is determined by thenoncontact proximity communication unit 2.

As illustrated in FIG. 20, the security controller 4 receives aninstruction signal φinst and carries out the above-mentioned low powerconsumption control. This instruction signal corresponds to the resultof determination of battery voltage VDDb by the voltage monitoringcircuit 30B of the noncontact proximity communication unit 2. Thevoltage monitoring circuit 30B is implemented by the determinationfunction of the operating voltage determination and selection circuit 13described with reference to FIG. 2. That is, it uses the function fordetermining whether or not the battery voltage VDDb is higher than apredetermined voltage and passes the result of this determination to thecontrol unit 17 in FIG. 2. The control unit 17 outputs an instructionsignal φinst to the security controller 4. This example is based on theassumption that the predetermined voltage is equal to the specifiedvoltage Vref. When the battery voltage VDDb is higher than thepredetermined voltage, the instruction signal φinst is set to highlevel. When the battery voltage VDDb is equal to or lower than thepredetermined voltage, the instruction signal φinst is set to low level.In the security controller 4, as illustrated in FIG. 21 as an example,the noncontact proximity communication interface circuit 23 receives theinstruction signal φinst. The received instruction signal φinst is usedin, for example, the selection of a program start address described withreference to FIG. 11. In this case, the processing is carried out asillustrated in FIG. 22. That is, when the power to the securitycontroller 4 is turned on, the level of the instruction signal φinst isdetermined (S7). When the signal is at high level (that is, the batteryvoltage VDDb is higher than a predetermined voltage such as 2.2V), forexample, the following processing is carried out: the address of thefirst start address register (SAREG_F) 61 is loaded to the programcounter (PC) of the processor 21 (S2). Then the execution of the firstprogram is started at the loaded address and all the functions of thesecurity controller 4 are made available (S3). Meanwhile, when the levelof the instruction signal φinst is low (that is, the battery voltageVDDb is equal to or lower than the predetermined voltage such as 2.2V),the following processing is carried out: the address of the second startaddress register (SAREG_S) 62 is loaded to the program counter (PC) ofthe processor 21 (S4). Then the execution of the second program isstarted at the loaded address and in the security controller 4, onlysecurity processing for noncontact proximity communication is madeavailable (S5). The mode for low power consumption control using theinstruction signal φdt may be any of the first mode to the third mode.In case of application to power supply/interruption control or the like,the instruction signal φinst only has to be supplied from the noncontactproximity communication interface circuit 23 to the power supply controlcircuit 24. In the example in FIG. 22, voltage level is determined onlywhen power supply is turned on. Instead, it may be monitored as requiredor may be constantly monitored and the state of the security controllermay be modified according thereto.

<<Determination of Battery Voltage by Both Mobile Communication Unit andNoncontact Proximity Communication Unit>>

Last, description will be given to a seventh control mode with low powerconsumption in which the battery voltage VDDb is determined by both thenoncontact proximity communication unit 2 and the mobile communicationunit 3.

As illustrated in FIG. 23 as an example, the noncontact proximitycommunication unit 2 includes the voltage monitoring circuit 30B and themobile communication unit 3 includes a voltage monitoring circuit 30C.This is a circuit for determining the battery voltage VDDb, similar tothe voltage monitoring circuit 30B. When it is determined by the voltagemonitoring circuit 30B that the battery voltage VDDb has become equal toor lower than a specified voltage, the noncontact proximitycommunication unit 2 issues the command NCMD to the security controller4. Meanwhile, when it is determined by the voltage monitoring circuit30C that the battery voltage VDDb is higher than a specified voltage,the mobile communication unit 3 issues a command MCMD to the securitycontroller 4. As illustrated FIG. 24, the command MCMD is received bythe mobile communication unit interface circuit 22 and the command NCMDis received by the noncontact proximity communication unit interfacecircuit 23. When the security controller 4 receives the command MCMD, itinstructs the following: starting the supply of power Vdd2 describedwith reference to FIG. 5; increasing the frequency of the clock signalCK described with reference to FIG. 7 and FIG. 8; starting the supply ofthe clock signal CK1 described with reference to FIG. 9; or the like.When the security controller 4 receives the command NCMD, meanwhile, itinstructs the following: interrupting the supply of power Vdd2 describedwith reference to FIG. 5; reducing the frequency of the clock signal CKdescribed with reference to FIG. 7 and FIG. 8; interrupting the supplyof the clock signal CK1 described with reference to FIG. 9; or the like.As illustrated in FIG. 25, therefore, the following processing iscarried out on a case-by-case basis as follows: when the command MCMD isissued to the security controller 4, all the functions of the securitycontroller 4 are made available (S3); and when the command NCMD isissued to the security controller 4, only security processing fornoncontact proximity communication is made available (S5). The processorresponds to a command and low power consumption control is therebycarried out. Therefore, this processing largely depends on a differencefrom software to software (the operating program of the processor) andthus the control mode with low power consumption can be easilycustomized to the actual use environment.

Up to this point, concrete description has been given to the inventionmade by the present inventions with reference to embodiments. However,the invention is not limited to these embodiments and can be variouslymodified without departing from its subject matter, needless to add.

Some examples will be taken. The operating voltage determination andselection circuit 13 of the noncontact proximity communication unit maybe so configured that the following is implemented: it outputs batteryvoltage VDDb as operating voltage VDDA until the battery voltage VDDbbecomes equal to or lower than a predetermined voltage. Wirelesscommunication longer in communication distance than noncontact proximitycommunication is not limited to mobile communication and may be wirelessLAN communication or the like. Noncontact proximity communication neednot be limited to that compliant with the following standards: astandard for noncontact IC cards internationally standardized inaccordance with the ISO/IEC 14443 (proximity cards: communicationdistance of 10 cm or below) or an equivalent standard; or the ISO/IEC15693 for the VICC type or an equivalent standard. It may be modified asappropriate. The invention is applicable not only to cellular phones butalso to various types of mobile communication terminal devices.

What is claimed is:
 1. A mobile communication terminal devicecomprising: a noncontact proximity communication unit carrying outnoncontact proximity communication; a wireless communication unitcarrying out wireless communication longer in communication distancethan the noncontact proximity communication and input/output control forthe wireless communication; a security controller utilized in securityprocessing for the noncontact proximity communication unit and thewireless communication unit; and a battery, wherein the noncontactproximity communication unit receives both electromagnetic field powerfrom a carrier in noncontact proximity communication and battery powerfrom the battery, wherein the noncontact proximity communication unitsupplies, as an operating supply power to the security controller, oneof the electromagnetic field power and the battery power which isselected depending upon a voltage of the battery, wherein the securitycontroller determines whether or not voltage from power supplied fromthe noncontact proximity communication unit has reached a specifiedlevel and, when it is determined that the specified level has not beenreached, carries out control so as to reduce the electricity consumptionof the security controller, wherein when the battery voltage is higherthan a predetermined voltage, the noncontact proximity communicationunit supplies the electromagnetic field power as the operating supplypower to the security controller if the electromagnetic field power isproduced, and supplies the battery power as the operating supply powerto the security controller if the electromagnetic field power is notproduced, and wherein when battery voltage is lower than thepredetermined voltage, the noncontact proximity communication unitsupplies the electromagnetic field power as the operating supply powerto the security controller if the electromagnetic field power isproduced, and interrupts the supply of the battery power to the securitycontroller.
 2. The mobile communication terminal device according toclaim 1, wherein the security controller includes a clock controlcircuit generating a synchronous clock signal for internal operation,and wherein when it is determined that the specified level has not beenreached, the clock control circuit reduces the frequency of thesynchronous clock signal as compared with when it is determined thespecified level has been reached.
 3. The mobile communication terminaldevice according to claim 1, wherein the security controller includes aclock control circuit generating a synchronous clock signal for internaloperation, and wherein when it is determined that the specified levelhas not been reached, the clock control circuit interrupts the supply ofa synchronous clock signal to a circuit utilized only in securityprocessing for the wireless communication unit.
 4. The mobilecommunication terminal device according to claim 1, wherein when it isdetermined that the specified level has not been reached, the securitycontroller interrupts the supply of operating power supply to a circuitutilized only in security processing for the wireless communicationunit.
 5. The mobile communication terminal device according to claim 1,wherein the security controller includes: a program memory unit; aprocessor executing a program held by the program memory unit; a firstcircuit used in security processing for the wireless communication unit;and a second circuit used in security processing for the noncontactproximity communication unit, and wherein the program memory holds: afirst initialization program for initializing a circuit used in securityprocessing for the wireless communication unit; a second initializationprogram for initializing a circuit used in security processing for thenoncontact proximity communication unit; a first security processingprogram used in security processing for the wireless communication unit;and a second security processing program used in security processing forthe noncontact proximity communication unit.
 6. The mobile communicationterminal device according to claim 5, wherein the program memory unitincludes: a first program memory unit for storing the firstinitialization program and the first security processing program; and asecond program memory unit for storing the second initialization programand the second security processing program, wherein a first operationmode in which operating power supply is supplied both to the firstprogram memory unit and to the second program memory unit or a secondoperation mode in which operating power supply is supplied only to thesecond program memory unit is selectable, and wherein the secondoperation mode is selected when the supply of operating power supplyutilized only in security processing for the wireless communication unitis interrupted.
 7. The mobile communication terminal device according toclaim 6, wherein the processor execute the first initialization programand the second initialization program to carry out initializationprocessing when it is determined at power-on reset that the voltage hasreached a specified level, and executes the second initializationprogram to carry out initialization processing when it is determinedthat the voltage has not reached the specified level.
 8. The mobilecommunication terminal device according to claim 1, wherein thespecified voltage and the predetermined voltage are equal to each other.9. The mobile communication terminal device according to claim 1,wherein the noncontact proximity communication unit includes a selectioncircuit that receives the electromagnetic field power and the batterypower, and selects one of the electromagnetic field power and thebattery power to be supplied as the operating supply power to thesecurity controller.
 10. A mobile communication terminal devicecomprising: a battery; a security controller; and a noncontact proximitycommunication unit carrying out noncontact proximity communication,wherein the noncontact proximity communication unit receives bothelectromagnetic field power from noncontact proximity communication andbattery power from the battery, wherein the noncontact proximitycommunication unit supplies, as an operating supply power to thesecurity controller, one of the electromagnetic field power and thebattery power which is selected depending upon a voltage of the battery,wherein when the battery voltage is higher than a predetermined voltage,the noncontact proximity communication unit supplies the electromagneticfield power as the operating supply power to the security controller ifthe electromagnetic field power is produced, and supplies the batterypower as the operating supply power to the security controller if theelectromagnetic field power is not produced, and wherein when batteryvoltage is lower than the predetermined voltage, the noncontactproximity communication unit supplies the electromagnetic field power asthe operating supply power to the security controller if theelectromagnetic field power is produced, and interrupts the supply ofthe battery power to the security controller.
 11. The mobilecommunication terminal device according to claim 10, further comprising:a wireless communication unit, wherein the security controller providesa voltage based on the operating supply power to the wirelesscommunication unit.
 12. The mobile communication terminal deviceaccording to claim 10, wherein the security controller includes a powercontroller that determines whether a voltage of the operating supplypower reaches a certain voltage level, wherein the power controllercarries out control so as to reduce the electricity consumption of thesecurity controller when the power controller determines that thecertain voltage level is not reached.
 13. The mobile communicationterminal device according to claim 12, wherein the power controllerincludes: a voltage monitoring circuit monitoring the voltage of theoperating supply power; a first power supply unit supplying power to anoncontact proximity communication function unit; and a second powersupply unit supplying power to a mobile communication function unit,wherein the voltage monitoring circuit prevents the second power supplyunit from supplying power to the mobile communication function unit whenthe certain voltage level is not reached.
 14. The mobile communicationterminal device according to claim 13, wherein the voltage monitoringcircuit includes: a reference voltage generating circuit generating avoltage of the certain voltage level; and a comparator outputting acomparison signal based on a comparison of the reference voltage and thevoltage of the operating supply power.
 15. A mobile communicationterminal device comprising: a battery; a security controller; and anoncontact proximity communication unit carrying out noncontactproximity communication, wherein the noncontact proximity communicationunit includes an operating voltage determination and selection circuithaving a first terminal that receives a first voltage produced bynoncontact proximity communication and a second terminal that receives abattery voltage, wherein the operating voltage determination andselection circuit selects one of the first voltage and the batteryvoltage to be output as an operating supply voltage to the securitycontroller, depending on the battery voltage, wherein when the batteryvoltage is higher than a predetermined voltage, the operating voltagedetermination and selection circuit outputs the first voltage as theoperating supply voltage to the security controller if the first voltageis produced, and outputs the battery voltage as the operating supplyvoltage to the security controller if the first voltage is not produced,and wherein when battery voltage is lower than the predeterminedvoltage, the operating voltage determination and selection circuitoutputs the first voltage as the operating supply voltage to thesecurity controller if the first voltage is produced, and interrupts thesupply of the battery voltage to the security controller.
 16. The mobilecommunication terminal device according to claim 15, further comprising:a wireless communication unit, wherein the security controller isutilized in security processing for the noncontact proximitycommunication unit and the wireless communication unit, and wherein thesecurity controller provides a voltage based on the operating supplyvoltage to the wireless communication unit.